Some tax returns can take longer to process than others for many reasons, including when a return:
Includes errors, Is incomplete, Is affected by identity theft or fraud, includes a claim filed for an Earned Income Tax Credit or an Additional Child Tax Credit. Or includes a Form 8379, Injured Spouse Allocation, which could take up to 14 weeks to process
The IRS will contact you by mail when or if they need more information to process your return.